U.S. patent number 5,823,797 [Application Number 08/790,298] was granted by the patent office on 1998-10-20 for connector-combined unit case, method of molding thereof, and mold for molding thereof.
This patent grant is currently assigned to Yazaki Corporation. Invention is credited to Norio Sugiyama.
United States Patent |
5,823,797 |
Sugiyama |
October 20, 1998 |
Connector-combined unit case, method of molding thereof, and mold
for molding thereof
Abstract
A connector-combined unit case comprises a unit case portion for
containing electric components; a connector portion for connecting
the unit case to a mating connector, said unit case portion and
said connector portion each being sealable against external air; a
connection portion integrally connecting said unit case portion and
said connector portion; and conductors embedded in layers in said
connection portion, each extending to connect said unit case
portion with said connector portion. This unit case does not
require an apt-to-fail, costly and complex slide core-equipped
mold, is free from troubles such as a short-circuit, corrosion of
internal components and the like, enables easy coupling and
decoupling of a mating connector, and does not require the mating
connector to be changed in shape.
Inventors: |
Sugiyama; Norio (Haibara-gun,
JP) |
Assignee: |
Yazaki Corporation (Tokyo,
JP)
|
Family
ID: |
11947169 |
Appl.
No.: |
08/790,298 |
Filed: |
January 31, 1997 |
Foreign Application Priority Data
|
|
|
|
|
Feb 2, 1996 [JP] |
|
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8-017555 |
|
Current U.S.
Class: |
439/76.1; 439/66;
29/883 |
Current CPC
Class: |
H01R
43/18 (20130101); H01R 43/24 (20130101); H01R
9/2458 (20130101); Y10T 29/4922 (20150115) |
Current International
Class: |
H01R
43/20 (20060101); H01R 43/24 (20060101); H01R
43/18 (20060101); H01R 9/24 (20060101); H01R
009/09 () |
Field of
Search: |
;439/34,76.1,66,736
;29/854,855,856,883 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Nguyen; Khiem
Attorney, Agent or Firm: Armstrong, Westerman, Hattori,
McLeland & Naughton
Claims
What is claimed is:
1. A connector-combined unit case molded in one-piece
comprising:
a unit case portion for containing electric components therein;
a connector portion for connecting said unit case to a mating
connector, said connector portion being sealable against external
air when coupled to said mating connector;
a connection portion connecting said unit case portion and said
connector portion;
conductor means embedded as inserts during molding and extending to
connect an interior of said unit case portion with said connector
portion, said unit case portion having holes through which said
conductor means are exposed and which are formed by holding means
used to hold said conductor means in position during molding, said
connection portion having no such holes;
grooves are provided at opposite sides of said unit case portion
for receipt therein of means for sealing said unit case portion
against external air; and
a hollow space located above said connection portion and separating
said unit case portion from said connector portion so that
terminals at an end of said connector portion are easily accessible
for connection to said mating connector.
2. The unit case according to claim 1, wherein said conductor means
comprises a plurality of conductors in spaced layers in said
connection portion, each extending to connect said interior of said
unit case portion with said connector portion.
3. The unit case according to claim 1, wherein said unit case
portion, for containing electric components therein, opens in a
same direction as a coupling direction of said connector portion to
said mating connector.
4. A method of molding a connector-combined unit case, comprising
the steps of:
providing a unit case portion for containing electric components
therein, a connector portion for connecting said unit case to a
mating connector, said connector portion being sealable against
external air when coupled to said mating connector, a connection
portion connecting said unit case portion and said connector
portion, conductor means embedded as inserts during molding and
extending to connect an interior of said unit case portion with
said connector portion, said unit case portion having holes through
which said conductor means are exposed and which are formed by
holding means used to hold said conductor means in position during
molding, said connection portion having no such holes, grooves are
provided at opposite sides of said unit case portion for receipt
therein of means for sealing said unit case portion against
external air, and a hollow space located above said connection
portion and separating said unit case portion from said connector
portion so that terminals at an end of said connector portion are
easily accessible for connection to said mating connector;
setting conductor means inside dies before the dies are
clamped;
holding said conductor means in place with preliminary holding
means before resin is introduced into said dies;
retracting said preliminary holding means while said resin is being
introduced into said dies to release the hold of said conductor
means; and
filling an empty space formed by said step of retracting said
preliminary holding means with resin.
5. The method according to claim 4, wherein said conductor means
comprises a plurality of conductors set in spaced layers to be
embedded in molded material.
6. The method according to claim 5, wherein said plurality of
conductors are preassembled as a set in a spaced manner with an
auxiliary means of insulating material to be set inside said
dies.
7. The method according to claim 6, wherein said auxiliary means is
formed from a similar resin as that for forming said unit case.
8. A mold for molding a connector-combined unit case, said mold and
connector-combined unit case in combination comprising:
providing a unit case portion for containing electric components
therein, a connector portion for connecting said unit case to a
mating connector, said connector portion being sealable against
external air when coupled to said mating connector, a connection
portion connecting said unit case portion and said connector
portion, conductor means embedded as inserts during molding and
extending to connect an interior of said unit case portion with
said connector portion, said unit case portion having holes through
which said conductor means are exposed and which are formed by
holding means used to hold said conductor means in position during
molding, said connection portion having no such holes grooves are
provided at opposite sides of said unit case portion for receipt
therein of means for sealing said unit case portion against
external air, and a hollow space located above said connection
portion and separating said unit case portion from said connector
portion so that terminals at an end of said connector portion are
easily accessible for connection to said mating connector; and
said mold including preliminary holding means for holding conductor
means in place before resin is introduced into dies of said mold,
said holding means being retracted while said resin is being
introduced into said dies to release a hold of said conductor
means.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a connector-combined unit case having a
unit case portion for accommodation therein of electric components
and a connector portion which connects the unit case with a mating
connector, and also to a method of molding the unit case, and a
mold for molding the unit case.
2. Description of the Related Art
An example of a conventional connector-combined unit case B is
shown in section in FIG. 8, which is comprised of a unit case
portion 1' and a male connector portion 2'. Not-shown various
electric components such as an electronic circuit are contained in
the interior 1a' of the unit case portion 1'. The connector portion
2' is of a waterproof structure adapted to become airtight on
connection with a mating connector, and has therein terminals 3a'
and 4a' which are integral parts of respective busbars 3' and 4'
and serve to make electric connections with a mating connector.
These busbars 3' and 4' are integrally embedded as inserts in
layers in the molded material constituting a unit case bottom 1b',
and integrally provided with contacts 3b' and 4b' for electric
connection with the various electric components in the unit case
interior 1a' and contacts 3c' and 4c' extended at the rear surface
side of the unit case bottom 1b'.
This unit case B with a connector is of a structure which becomes
airtight during its use. In other words, grooves 1c' are provided
at longitudinally spaced positions on the rear surface of the unit
case bottom 1b' and on end surfaces of the longitudinally opposite
walls of the unit case, each for receiving an O-ring (not shown)
which makes the unit case airtight when the unit case is mounted,
i.e., when the unit case is at the side of its bottom 1b' fixed on
a wall surface and at the opposite side covered with a lid (not
shown). These O-rings prevent the unit case after mounted from
being penetrated from outside with a corrosive gas, water or the
like.
To mold such a connector-combined unit case having a plurality of
busbars as inserts, the busbars are at their terminals 3a' and 4a'
held in position by a molding die and at the same time held inside
the cavity of the mold by die-carried busbar-holding pins, so as to
prevent the mutual contact of the busbars inside the molded product
and a short-circuit therebetween. After completion of the molding,
such busbar-holding pins leave corresponding pin holes 5' in the
molded product as shown in FIG. 8.
Such a connector-combined unit case is excellent, capable of being
sealed against water (air) when mounted as mentioned above, but has
a drawback that, when mounted on a wall surface, the coupling and
decoupling operations of a mating connector to and from the unit
case are troublesome, since the coupling and decoupling operations
are effected in a side direction of the unit case (in a direction
parallel to the wall surface). Besides, such a unit case, when
mounted, requires a space aside within which the mating connector
is moved to be coupled and decoupled.
In addition, because of its structure in which the connector
portion forms an undercut, the unit case requires for its molding a
mold with a slide core. Further, a plurality of slide cores each
having a complicated shape and structure are in many cases required
for forming this connector portion, since the connector portion
needs to have a complex shape for its functions such as
positioning, falling-off prevention and waterproofing. As a result,
there has been a drawback that the mold becomes costly, is easy to
cause failures, and has a low product yield and productivity,
resulting in the high production cost of the unit case.
Here, it may be deemed possible to solve the above-mentioned
problems of the coupling space and undercut by providing a
connector portion to have a coupling direction which is the same as
the opening direction of the unit case. In this case, however,
there are conventionally practically no means which prevent the
mutual contact of busbars inside the cavity during molding,
resulting in the connector portion and unit case portion requiring
to be formed in close contact with each other. Consequently, the
shape of the connector portion is limited to be female, which in
turn requires the mating connector to be changed in shape, i.e., to
a male connector, resulting in the cost increased and in difficulty
in obtaining sufficient airtightness due to limitations to the
shape.
If, as means to prevent the mutual contact of busbars inside the
cavity during molding, such busbar-holding pins as used to hold the
busbars in place in the unit case portion during molding are for
example applied, these pins leave pin holes in the molded product
which expose the internal busbars to the outside. These pin holes
are formed at an area outside the range covered by the O-ring
grooves and are likely to not only cause a short circuit, but also
allow a corrosive gas or moisture to penetrate into the case and
connector through the pin holes and small gaps inevitably made
between the busbars and the case by a difference in their materials
and corrode the inside to cause a failure. Such externally opened
pin holes may possibly be covered with caps or filled with an
adhesive, which, however, is not practical, requiring labor hours
and in particular being unreliable for a long-term use under the
environment of vibrations as in an automobile and the like.
SUMMARY OF THE INVENTION
This invention has been accomplished to overcome the above
drawbacks and an object of this invention is to provide a
connector-combined unit case having a waterproof structure, which
does not require an apt-to-fail, costly and complex slide
core-equipped mold, is free from troubles such as a short-circuit,
corrosion of internal components and the like, enables easy
coupling and decoupling of a mating connector without requiring a
coupling and decoupling space by the side of the unit case, and
does not require the mating connector to be changed in shape.
Another object of this invention is to provide a method of molding
the unit as mentioned above. A further object of this invention is
to provide a mold for molding the same.
In order to attain the object, according to an aspect of this
invention, there is provided a connector-combined unit case
comprising: a unit case portion for containing electric components
therein; a connector portion for connecting the unit case to a
mating connector, the unit case portion and the connector portion
each being sealable against external air; a connection portion
integrally connecting the unit case portion and the connector
portion; and conductor means embedded in the connection portion to
be unexposed to external air, the conductor means extending to
connect an interior of the unit case portion with the connector
portion.
According to another aspect of this invention, there is provided a
method of molding a connector-combined unit case as claimed in
claim 1, comprising the steps of: setting conductor means inside
dies before the dies are clamped; holding the conductor means in
place with preliminary holding means before resin is introduced
into the dies; retracting the holding means during the introduction
of resin into the dies to release the hold of the conductor means;
and filling an empty space formed by the retraction of the
preliminary holding means with resin.
According to a further aspect of this invention, there is provided
a mold for molding a connector-combined unit case as claimed in
claim 1, comprising: preliminary holding means for holding
conductor means in place before resin is introduced into dies of
the mold, the holding means being retracted during the introduction
of resin into the dies to release the hold of the conductor
means.
The above and other objects, features and advantages of this
invention will become apparent from the following description and
the appended claims, taken in conjunction with the accompanying
drawings in which like parts or elements are denoted by like
reference characters.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a connector-combined unit case
according to one embodiment of this invention;
FIG. 2A is a sectional view of a model of a mold used to mold the
connector-combined unit case according to this invention;
FIG. 2B is a view of a cam mechanism used in molding the unit case
as in FIG. 2A;
FIG. 2C is a perspective view of a plurality of conductors
preliminarily locked relative to each other with an auxiliary means
of insulating material to be set inside the mold;
FIG. 3 is a sectional view of the mold model showing the first step
of molding according to this invention where busbars are set inside
the mold;
FIG. 4A is a sectional view of the mold model showing the second
step of molding according to this invention where dies of the mold
are clamped;
FIG. 4B is a partial enlarged view of FIG. 4A;
FIG. 5A is a sectional view of the mold model showing the third
step of molding according to this invention where resin is
introduced into the cavity of the mold and the hold of the busbars
is released;
FIG. 5B is a partial enlarged view of FIG. 5A;
FIG. 6A is a sectional view of the mold model showing the fourth
step of molding according to this invention where the clamp of the
dies is released;
FIG. 6B is a partial enlarged view of FIG. 6A;
FIG. 7 is a sectional view of the mold model showing the final step
of molding according to this invention where the product is removed
from the mold; and
FIG. 8 is a sectional view of a conventional connector-combined
unit case.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of this invention will now be described with reference
to the attached drawings.
While in these embodiments, busbars are shown to be arranged in two
layers in the unit case, this application is also applicable to the
case where busbars are arranged in three or more layers.
FIG. 1 is a sectional view of a connector-combined unit case A
(terminal case for an automotive antilock braking system) according
to one embodiment of this invention.
This unit case A is comprised of a unit case portion 1 in the
interior 1a of which are accommodated various electric components
such as an electric circuit, a connector portion 2, and a
connection portion 6 that connects these portions 1 and 2. The
connector portion 2 serves as a connector of a waterproof structure
adapted to become airtight on connection with a mating connector,
and has inside thereof terminals 3a and 4a for electric connection
with the mating connector, which are integral with busbars 3 and 4,
respectively. Busbars 3 and 4 are embedded as inserts in two spaced
layers in the molded material constituting a unit case bottom 1b,
and integrally provided with respective contacts 3b and 4b for
electric connection with the various electric components contained
in the unit case interior 1a and respective contacts 3c and 4c
provided on the rear surface side of the unit case bottom 1b.
The busbars, disposed in spaced layers as mentioned above, can
provide a multiplicity of branch circuits without the fear of
causing a short-circuit therebetween.
This connector-combined unit case A is of a structure adapted to
become airtight when mounted. In other words, at two longitudinally
spaced positions on the rear surface of its bottom 1b and on end
surfaces of its longitudinally opposite walls, grooves 1c are
provided, each for receipt therein of an O-ring so that the unit
case 1 becomes airtight when fixed at the side of its bottom 1b to
a wall surface and covered at the opposite side with a lid (not
shown). Thus, in use, an external corrosive gas, water or the like
is prevented from entering the unit case.
To mold the connector-combined unit case A having a plurality of
busbars as inserts, the busbars 3 and 4 are held in position during
molding by a die and at the same time held by die-carries
busbar-holding pins so as to prevent contact of the busbars inside
the molded product and a short-circuit therebetween. The
busbar-holding pins leave pin holes 5 in the product as shown in
FIG. 1.
The connection portion 6 of the connector-combined unit case A
serves to provide the freedom to select the coupling direction of
the connector portion 2 and not to restrict the shape of the mating
connector to be coupled to the connection portion 2. In other
words, due to the connection portion 2, the mating connector may be
of a male or female type, and the freedom in designing the mating
connector is increased and the necessity of changing the design of
the mating connector is eliminated, making it possible to use a
versatile connector. Consequently, an improvement in airtightness
between the connectors coupled can be made.
Further, by providing the connector portion 2 to have a coupling
direction which is the same as the opening direction of the unit
case 1 as shown in FIG. 1, the undercut formation of the connector
portion 2 is avoided, thereby making it unnecessary to use a mold
with a slide core which is costly, complex and apt to fail.
Besides, the coupling of a mating connector to the connector
portion is facilitated, and the space required aside the unit case
A on a wall surface for moving the mating connector into and out of
coupling with the connector portion becomes unnecessary.
With such a structure employed, a complex shape can be imparted to
the connector portion by adjusting the parting line of the dies,
which complex shape is required for the functions of the connector
portion such as the positioning at the time of mounting, prevention
of disengagement and waterproofing.
A plurality of busbars (busbars 3 and 4 in FIG. 1) are arranged in
layers in the connection portion 6. It is to be noted that, in this
area which is out of the range covered by the O-rings, die-carried
busbar-holding pins cannot be used to hold these busbars in place
during molding. In other words, the use of the holding pins leaves
pin holes in the product, which open to the outside in this area of
the connection portion 6. Consequently, a fear arises that water
enters through the pin holes to cause a short-circuit, or a
corrosive gas, moisture or the like penetrates inside the unit case
portion 1 and/or connector portion 2 through the pin holes and
small gaps inevitably made between the busbars and the resin due to
the material difference to corrode the internal components and
their cotacts.
An example of a molding method and of a mold for solving such
problem will now be described with reference to FIGS. 2 to 7. These
figures show in sequence the model of the mold in section in each
step of the molding (only essential portions including the
connector portion and connection portion) and some of its portions
in enlarged scale.
The mold shown in section in FIG. 2A is comprised of an upper die
11 and a lower die 12. The upper die 11 is provided with an upper
core 11a, an upper air cylinder 11b, a cam mechanism 11c and an
upper adjusting mean 11d, while the lower die 12 is provided with a
lower core 12a, a lower air cylinder 12b, a cam mechanism 12c, a
lower adjusting means 12d and a product ejecting pin 12e.
The upper core 11a and the lower core 12a cooperate with each other
to provide preliminary holding means and are each movable into and
retractable from the cavity defined between the upper and lower
dies by the respective upper and lower air cylinders 11b and 12b
and cam mechanisms 11c and 12c. In other words, the advancement of
each cylinder shaft causes the individual core to move into the
cavity via the respective cam mechanism, and the retraction of each
cylinder shaft causes the individual core to retract from the
cavity via the respective cam mechanism. (The lower cam mechanism
is partially shown in perspective in FIG. 1B, with the lower core
12a shown separated.) The advancement and retraction length of each
core is adjustable by means of the respective adjusting means 11d,
12d. The product ejecting pin 12e is for ejecting the product from
the die after completion of the molding and is coupled to a die
opening and closing mechanism (not shown) to be driven during the
opening process of the dies to eject the product.
Insert-forming busbars 3 and 4 are arranged inside the dies. For
this purpose, if the busbars are assembled as a set by means of a
hold connector 7 as shown in FIG. 2A, their mounting will be
facilitated and mounting errors will be prevented. The hold
connector 7 also serves to keep the busbars separated from each
other. The hold connector 7 is of an insulating material except
some special cases, which material is preferably the same as that
for the connector-combined unit case so that it becomes integral
with the resin later injected to mold the unit case. In this way,
post-molding strains can be excluded from the product. Busbars 3
and 4 held by the hold connector 7 are shown in partial perspective
in FIG. 2C.
FIG. 3 shows the hold connector 7 and busbars 3 and 4 set in place
in the lower die 12.
FIG. 4A shows the upper and lower dies 11 and 12 clamped to form
the cavity 13, at which the busbar 3 is held between the upper and
lower cores 11a and 12a moved into the cavity. (FIG. 4B is an
enlarged view of the portion encircled in FIG. 4A.) The busbar 4 is
held between the upper core 11a and the hold connector 7. Into the
cavity 13 is then introduced resin which also serves to hold the
busbars in place as mentioned above to prevent their displacement
and contacting with each other.
FIG. 5A shows the state immediately before the completion of the
resin introduction. In this instance, the hold of the busbar by the
cores 11a and 12a is released as best shown in partial enlargement
in FIG. 5B. The upper and lower cores 11a and 12a are retracted to
release the hold of the busbar, and the empty spaces made by the
retraction of the cores are filled with the resin introduced
thereafter and before the completion of the resin introduction,
thereby to prevent the internal busbars from being exposed. The
timing of the core retraction needs to be suitably adjusted because
if it is too early, the busbar will be released at a time when the
flow of the resin is still large to cause its displacement, while
on the other hand if too late, the resin will not be introduced
into the empty spaces made by the retraction of the cores,
resulting in the exposure of the busbars to the outside and poor
airtightness (waterproofness).
As mentioned above, if the material for the hold connector 7 is the
same as the resin introduced into the cavity, a product is obtained
which is faborable, free of cracks and the like.
FIG. 6A shows the state where the clamp is released and FIG. 6B is
a partial enlarged view of FIG. 6A. FIG. 7 shows the final step
where the product ejecting pin 12e projects to eject the product 15
from the die and obtain the connector-combined unit case according
to this invention.
The method as described above is widely applicable to the
production of not only a connector-combined unit case, but also
various electric devices such as an electric junction box,
switching case and the like, since the above method provides a
molded product with an electric insert reliably insulated from the
outside only by giving very simple structures to the upper and
lower dies.
Having now fully described the invention, it will be apparent to
one of ordinary skill in the art that many changes and
modifications can be made thereto without departing from the spirit
and scope of the invention as set forth herein.
* * * * *